It's funny that iTunes says mono HE-AAC files created by itself as stereo HE-AAC v2.It actually is not HE-AAC v2 and not using any SBR extensions including PS. I confirmed this looking into bitstream (using debugger).In this case, QuickTime player and Mediainfo are correct.

It's funny that iTunes says mono HE-AAC files created by itself as stereo HE-AAC v2.It actually is not HE-AAC v2 and not using any SBR extensions including PS. I confirmed this looking into bitstream (using debugger).In this case, QuickTime player and Mediainfo are correct.

Oh yeah, for the LC file, foobar says stereo and itunes / quicktime says mono. So the behaviour for qaac is consistent with itunes and any "issue" is that caused by itunes only.

I think quicktime actually always says he v2 files are mono: i tested one encoded with nero aac.

Your HE AAC file IS mono, the decoder just outputs upmixed stereo. This is because of parametric stereo, which is always signalled implicitly. Because of that, the decoder upmixes ALL mono files to stereo, even if there is no PS in the file.

Your HE AAC file IS mono, the decoder just outputs upmixed stereo. This is because of parametric stereo, which is always signalled implicitly. Because of that, the decoder upmixes ALL mono files to stereo, even if there is no PS in the file.

Menno

What "decoder" is that quote referring to?

If Mediainfo is correct, all the below behaviors is wrong:Itunes encoded LC file with mono source is reported as LC stereo in foobar.Itunes encoded HE file with mono source is reported as HE stereo in foobar.Itunes encoded HE file with mono source is reported as HEv2 stereo in Itunes.

In all 3 cases: the software actually decodes to 2 channels, as verified by their "convert to wav" output.

Your HE AAC file IS mono, the decoder just outputs upmixed stereo. This is because of parametric stereo, which is always signalled implicitly. Because of that, the decoder upmixes ALL mono files to stereo, even if there is no PS in the file.

Menno

What "decoder" is that quote referring to?

If Mediainfo is correct, all the below behaviors is wrong:Itunes encoded LC file with mono source is reported as LC stereo in foobar.Itunes encoded HE file with mono source is reported as HE stereo in foobar.Itunes encoded HE file with mono source is reported as HEv2 stereo in Itunes.

In all 3 cases: the software actually decodes to 2 channels, as verified by their "convert to wav" output.

I think it is problem with foobar and itunes then.

The last test I am doing: Nero encoded HE(v1) with mono source:Itunes reported as HEv2 stereo.

So seems that Itunes is just reporting any HE files as "v2" and try decoding as stereo.

nu774, sorry I have to ask this, is there an option to remove the "Tool" tag while converting? I have few iOS projects and I would like to use Apple/TVBR for music files but I don't want to show how I converted them.

If not, could you create a new version with a "-notool" or similar option?

MP4 container minor fix: added "isom" to compatible brands.Also I started a new project [url="https://github.com/nu774/cafmux"]cafmux[/url] at github, which is a simple command line audio remuxer using CoreAudioToolbox.